An outer end of a seal element for a fixed scroll is extended to a position close to an end of an inside spiral wall of the fixed scroll, and an outwardly extended portion is formed at an outer periphery of a disc-shaped base plate of a movable scroll, so that a bottom surface of the movable scroll is always kept in a sliding contact entirely with the seal element during the orbital movement of the movable scroll. A thickness of the outwardly extended portion formed at the outer periphery of the disc-shaped base plate is made smaller than that of the disc-shaped base plate, so that the weight of the fluid machine can be smaller.
1. A scroll type fluid machine comprising:
a housing;
a converting means for collecting heat energy from working fluid and converting the collected heat energy into mechanical rotational energy by expanding the working fluid in an isenthalpic manner;
a shaft rotationally supported by the housing and having an eccentric shaft portion;
a movable scroll having a disc-shaped base plate and a spiral wrap, the movable scroll being operatively connected with the eccentric shaft portion so that the movable scroll moves with an orbital movement;
a fixed scroll having a base plate and a spiral wrap to be coupled with the movable scroll to form working chambers, volume of the working chambers being gradually increased when the movable scroll is rotated with its orbital movement and when the working chambers move from a center of the fixed scroll toward an outward direction;
a seal element provided on a front end of the spiral wrap of the fixed scroll, wherein an outer end of the seal element is extended to a position close to an end of an inside spiral wall of the fixed scroll wherein the end of the inside spiral wall corresponds to an outermost wall at which the outside spiral wall of the movable scroll is brought into and out of contact with the inside spiral wall of the fixed scroll in accordance with the orbital movement of the movable scroll; and
an outwardly extended portion formed at an outer periphery of the disc-shaped base plate of the movable scroll to form a part of a bottom surface of the disc-shaped base plate, so that the bottom surface of the disc-shaped base plate is always kept entirely in sliding contact with the seal element during the orbital movement of the movable scroll, wherein the thickness of the outwardly extended portion is less than that of the disc-shaped base plate of the movable scroll,
wherein an outer shape of the movable scroll is formed with an envelope curve, which is described on the bottom surface of the movable scroll by an outer edge of the seal element, when the movable scroll is rotated.
2. A scroll type fluid machine comprising:
a housing;
a converting means for collecting heat energy from working fluid and converting the collected heat energy into mechanical rotational energy by expanding the working fluid in an isenthalpic manner;
a shaft rotationally supported by the housing and having an eccentric shaft portion;
a movable scroll having a disc-shaped base plate and a spiral wrap, the movable scroll being operatively connected with the eccentric shaft portion so that the movable scroll moves with an orbital movement;
a fixed scroll having a base plate an spiral wrap to be coupled with the movable scroll to form working chambers, the volume of the working chambers being gradually increased when the movable scroll is rotated with its orbital movement and when the working chambers move from a center of the fixed scroll toward an outward direction;
a seal element provided on a front end of the spiral wrap of the fixed scroll, wherein an outer end of the seal element is extended to a position close to an end of an inside spiral wall of the fixed scroll wherein the end of the inside spiral wall corresponds to an outermost wall at which the outside spiral wall of the movable scroll is brought into and out of contact with the inside spiral wall of the fixed scroll in accordance with the orbital movement of the movable scroll; and
an outwardly extended portion formed at an outer periphery of the disc-shaped base plate of the movable scroll to form a part of a bottom surface of the disc-shaped base plate, so that the bottom surface of the disc-shaped base plate is always kept entirely in sliding contact with the seal element during the orbital movement of the movable scroll, wherein the thickness of the outwardly extended portion is less than that of the disc-shaped base plate of the movable scroll, wherein a thickness of the outwardly extended portion formed at the outer periphery of the disc-shaped base plate is made smaller than that of the disc-shaped base plate, except for such portions, a front side of which is opposed to the scroll wrap of the fixed scroll.
3. A scroll type fluid machine comprising:
a housing;
a converting means for collecting heat energy from working fluid and converting the collected heat energy into mechanical rotational energy by expanding the working fluid in an isenthalpic manner;
a shaft rotationally supported by the housing and having an eccentric shaft portion;
a movable scroll having a disc-shaped base plate and a spiral wrap, the movable scroll being operatively connected with the eccentric shaft portion so that the movable scroll moves with an orbital movement;
a fixed scroll having a base plate and a spiral wrap to be coupled with the movable scroll to firm working chambers, the volume of the working chambers being gradually increased when the movable scroll is rotated with its orbital movement and when the working chambers move from a center of the fixed scroll toward an outward direction; and
a seal element provided on a front end of the spiral wrap of the fixed scroll, wherein
an outer end of the seal element is extended to a position close to an end of an inside spiral wall of the fixed scroll,
the end of the inside spiral wall corresponds to an outermost wall at which the outside spiral wall of the movable scroll is brought into and out of contact with the inside spiral wall of the fixed scroll in accordance with the orbital movement of the movable scroll,
the diameter of the disc-shaped base plate of the movable scroll is such that a bottom surface of the movable scroll is always entirely maintained in sliding contact with the seal element during the orbital movement of the movable scroll, and
an outer portion of the disc-shaped base plate, which does not come m contact with any portion of the seal element during the orbital movement of the movable scroll, is cut out.
4. A scroll type fluid machine according to claim 3 , wherein the fixed scroll is integrally formed in the housing, a configuration of cross section in a plane perpendicular to the shaft is formed into an almost rectangular shape, and the end of the inside spiral wall of the fixed scroll is located at a position close to a corner of the rectangular-shaped fixed scroll.